Why does rendering on a PC take 10 seconds compared to 0.25 seconds in-camera?

There is no sensor that can produce a jpeg directly. The embedded jpeg, which is shot with the picture control settings, comes from what? Think a little about it.

The sequence is something like this:

• Sensor always a outputs raw data
• In camera computer renders a jpeg from raw data based on picture control settings
• If the camera is set to keep the raw file then in camera computer bundles raw data and jpeg (preview embedded jpeg) in a file == raw file
• In camera computer writes the raw file to card

If the camera is set to keep the jpeg only then it discards the raw data ​after processing and keeps only the jpeg file.

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Panagiotis